Get Legendary Studio Tones from your Tube Amp — Anywhere, at Any Volume.

OX is a premium reactive load box and guitar recording system, giving you perfectly studio-miked amp sounds from your favorite tube amp. OX lets you play and record your amp in its sweet spots — from huge clean tones and edge-of-breakup to fully cranked — at any volume level, and with mic, room, and speaker cabinet emulations at the turn of a knob.

Audition, tweak, and save more than 100 jaw-dropping custom Rigs from compatible iPad, or Mac/Windows computers.

The World’s Best Reactive Load Box

With decades of analog hardware engineering expertise, Universal Audio’s dream team of engineers set out to design a reactive load box that retains the tone, dynamics, and feel of your tube amp — no matter how much it’s attenuated. The goal was for your tube amp to “see” OX as an actual speaker — with continuously variable impedance and response — so you don’t lose a drop of tone or playing dynamics.

A Complete Guitar Recording System

OX’s front-panel, six-position RIG control allows you to quickly choose from complete setups — including emulated speaker cabinets, close mics, ambient room mics, and up to four simultaneous studio effects. OX is also the only guitar recording system to offer a complete selection of expertly placed room mics, giving you the authentic experience of pushing air while recording your cranked amp in a world-class tracking room.

Dynamic Speaker Modeling

UA’s groundbreaking Dynamic Speaker Modeling faithfully emulates speaker breakup, drive, and cone cry — an essential ingredient to authentic tube amp tones. Using the Speaker Breakup knob in the OX app, you can control the harmonics and sonic complexity that occurs only at certain frequencies and volume levels on various speakers — far beyond a static Impulse Response system — giving you the same sonic phenomenon that occurs with a real speaker cabinet.

All The Right Connections

Not only does OX Amp Top Box feature a front-panel headphone jack for silent practice with your cranked tube amp, it also sports a bevy of connections for all kinds of recording and live workflows. Stereo S/PDIF digital outputs via RCA and optical TOSLINK, as well as balanced TRS stereo line outputs with front panel level control, give you the necessary connections for studio monitors, DAW, or live mixing console inputs. Plus, you can connect any one, two, or three-button footswitch and toggle OX's studio-quality effects on and off.

A Beautiful Software App

Most guitar products do digital awkwardly. They’re ugly and hard to understand. The OX software app, on the other hand, offers slick, intuitive control over all of OX’s RIG settings via Wi-Fi — letting you tweak, store and recall hundreds of presets from your iPad, Mac, or Windows 10 computer. You can then save your six favorite tones onto OX’s front-panel RIG knob for instant recall in the studio or at a gig.

“OX does not disappoint. The room mics give your recorded tones character and realism, and the delays and the plate reverb sound expensive. It's easy to use, yet deep, and most importantly, fun. UA has hit it out of the park with OX!”– Pete Thorn(Don Henley, Melissa Etheridge)

“OX is a true game changer. New uses for it literally pop into my head every day. It’s head-and-shoulders above any product of its kind. For any guitarist who records his own tracks, OX is essential!”– Josh Smith(Taylor Hicks, Raphael Saadiq)

“I can use OX on the most critical piece of music and be 100% happy. The UA team knocked it out of the park with this genius piece of gear. It’s perfect for the hobbyist in a bedroom, to the highest professional environment, be it studio or stage. Yes, OX is that good!”– Lyle Workman(Beck, Sting)

Watch The Reviews

OX App & Manual

Customer Reviews

m. nelson

February 17, 2020

Updated Review: UA finally got it right

about a year or so, I left a review of the OX, and I definitely shared my pros and cons. However, After a recent firmware update that brought more cabinets, and an overall better sound, I...

Customer Reviews

OX Amp Top Box

Overall Rating

J. Romanchik

May 6, 2020

Make it hardwire-able!

Was REALLY looking forward to using this. But have been stuck using only the 6 presets on the front. Will not connect to WiFi. There is ZERO customer service! Dont want to return this but if i cant access the app there is no way it is worth $1300. ABSOLUTELY RIDICULOUS

m. nelson

February 17, 2020

Updated Review: UA finally got it right

about a year or so, I left a review of the OX, and I definitely shared my pros and cons. However, After a recent firmware update that brought more cabinets, and an overall better sound, I can say that this is the best of its kind.

About 2 years ago, My band "Ornimental" started to record our second record and one of our microphones crapped out right in the middle of guitar tracking. When we heard that UA was making the OX, We got in line to pay for it pretty much immediately. After recording with the OX out of the box, It took us a while to get something we liked, and we weren't 100% on the sound. We ended up with the 4x12 greenback "punch" for guitars, but it wasn't up to our standard.

I mentioned before that the OX was amazing for the old school guys that want that retro sound, but it's not too tone friendly with people desiring more modern sounds. Well, After their 2nd firmware release, I can say that everything sound incredible! Just have the V30 cabs in the library changed everything for us. Even though we can't go back to doing the guitars for the record, we are ready to tackle the next one with better tones!

The OX is the best piece of gear for guitar recording!

D. Williams

February 16, 2020

Innovative & Dynamic

Unparalleled build quality, a plethora of more-than-realistic cab and mic options, results in lush tube amp tones to die for. Great product. My only complaint is the limited either/or wifi or internet connection. Hopefully, you all will develop a direct connection between computer and the ‘Ox’, this would be great. Nonetheless, I am blown away.

J. Leyton

January 25, 2020

Guitarist/Producer

Love the OX and have had one since it came out. Rabear, you just get better and better. You are a real accomplished player now. Looking forward to hearing more from you.

M. Tuttle

December 21, 2019

Quite Useful

I bought one when they first came out and I've never had an issue. Updating via my Mac was no issue when following the instructions and having my iPad close by means it is very simple to change parameters at any moment.

S. Lauzon

November 27, 2019

Lots of issues.

I have the OX. I bought it about 7 months ago and it’s clumsy. Aside from the fact that you have to constantly switch WiFi to OX, then back to your router, even after you’ve set everything up! It’s ridiculous.

There’s been a update, which I was excited about briefly. Here’s why:

1. You need a usb flash drive to do this. It says you can do it over WiFi but not if you update the OX app first. My apps are setup for auto updates. So the firmware is incompatible and the app WILL NOT open because of this issue. I haven’t been able to open the app to change cabs or mics since nov 4th.

2. Customer service is awful. I’ve had a ticket out for 2 days now and no reply... nothing.

3. You may buy the wrong flash drive (as I did 2 times. Why two times? Well. It doesn’t say anywhere on the notes for the update which beans works. I’ve spent $30 and still can’t update firmware. The site says *try different one if not recognized. Yeah - cause I have lots of usb flash drives. They are almost obsolete....

4. If you have the issues I’ve had, it’s a glorified paperweight.

All of this is why I’m going to sell it at a 3-400$$ loss and go back to the easy to operate and use Mesa Cab Clone. I can’t honestly say I hear a 1000$$ difference anyway.

Sam L

G. Herrera

November 23, 2019

Faithful to this Unit

Having bought this when it first came out, I was really Loving what it did for my recordings, and now with the Update, OMG so Complete! I can get any tone I need Period! The ease of use just makes it fun and Inspiring, this is worth every penny and will never get rid of this Unit. Thanks UA

w. visbeen

November 17, 2019

No sleep but more than alive.

Bought the ox mainly for attenuator function. Speaker connector combo too short. While waiting for cable dived into the cab emulations and haven't slept since. Can't remember having had so much fun with my amp. Thank you so much!

K. Robinson

November 14, 2019

Awesome bit of kit!

Thank you for the new update!

I use the OX live all the time and having the footswitchable effects is brilliant now. I can now crank my amp (JTM 45) and get a volume boost for solos using the EQ on the OX. Super useful!

A. Walton

November 13, 2019

Epic bit of kit.

Absolutely love this , candy in my studio. The Nov 19 update is just glorious. Well done UA.

r. stepan

October 31, 2019

Wow we can use our 30 tube amps in our recording studio direct into Logic

This Ox sounds fantastic and we can dime our JCM 800’s and Silver Jubees Mesa
Orange etc and they sound fantastic. We use our FractalAxe Fx for some effects but
the cabs sims and UA quality is top drawer. Recording our clients without dragging out
a bunch of cabs is over...we do it all on theMac.
Fantastic piece of kit..great job guys....

J. Metzger

October 26, 2019

Dynamic

I am really impressed just wow ! I was skeptical at first but after using the ox to record some clean guitar i couldn’t believe how dynamic and easy the guitar was to control . This device is ahead of the heard if you ask me . There seems to be some sort of magic going on here , I can now record my guitar without second guessing myself because the ox makes it so easy to get a great tone and record in mono or stereo when I need without having to adjust a bunch of settings . You get the sound you like , hit record and you have professional sounding guitar tracks . Great job uad !! This paired with an Apollo is a match made in heaven .

O. Harkoma

October 14, 2019

Great tool for tube amps

I use this with my 87' Marshall 100W Silver Jubilee head, works and sounds great, only missing piece is really the V30 speaker model. Also tried it with small 20W Koch combo and it sounded completely crap with distortion, however pretty ok with clean channel. Seems like no one size fits all and perhaps you want to test with your tube amp before buying. I personally like the control over wifi, no issues using with iPad, Mac and now Windows also.

C. Holmes

October 5, 2019

Connection Woes

I find it insane that you can't connect the Ox to your computer via a USB or Firewire cord and have to rely on a wireless signal. The disconnections I kept encountering via the WiFi put me off on it entirely. I ended up returning it, which is a shame because I've been having a lot of problems with my Two Notes Torpedo Studio, which is the other loadbox I use, and was very hopeful that the Ox would be a worthwhile alternative. This is really a major design flaw that I'm stunned UAD hasn't done anything to address.

D. Nelson

August 15, 2019

It's absolutely amazing...for a specific audience

I've own this very well made, and fun to use load box. It's the guitar player's dream top box for studio, practicing, or even live shows if you know how to take care of it. I don't recommend taking it out on gigs because it is very fragile. I've owned this top box for over a year, and I can tell you what I think about it.

So my band "Ornimental" is a Hard Rock/Metal band that used this for our record we recorded and we got pretty great results...for anything besides heavier music. We used different cabs, and used a lot of the UA plug ins this came with. I thought it was really cool that they did that. Unfortunately, When it came to heavier tones, which my band uses most of the time, it just doesn't cut it. It's obvious that this was marketed to players that love tones that are more on the vintage side. There's really no way to get contemporary heavy tones with this box, and it's a little disappointing. I also heard the UA has no plans on adding any kind of V30, or other speakers that are good for the style, so that's a let down too. It's great for Rock, Country, Blues, Jazz, Funk, and any other style you can think of that doesn't require a lot of dirt. We got great results with other styles, but Harder styles just won't cut it here.

I'm sure that if I ever record with a different band thats a totally different style, this will do great, but the OX is made for vintage lovers and as much as I love vintage gear, I do need tones that are more modern and I feel like this would of blown away any other competitor.

I honestly believe that a V30 cab option would of been the answer to our issues. I'm not sure why the OX didn't come with it especially since it's arguably the most popular 12 inch guitar speaker ever aside from the Greenback. I've also heard that other people have asked if there will ever be an update with a V30 cab. That would be amazing!

It's an awesome piece of gear, but it's definitely not perfect. After some updates on a V30 option, and possibly more microphone options, I think it will be miles ahead of where it is now.

- Danny

S. Lauzon

June 16, 2019

Top Notch Top-Box

First off, this is a 5 Star item. I gave it four because if 2 simple things.
1.) you cannot be connected to the internet and the top box at the same time. The top box sends a WiFi-type signal you must connect to to make Cab/Mic adjustments. That’s kind of ridiculous. Almost everyone uses the internet on their pad while recording. It needs to be fixed.

2.) the options are limited where as TwoNote gives you 100’s of options.

So now with the cons out of the way. The sound is simply unmatched. The quality and ability this box performs with is, simply, amazing!

The little details UA took to make this thing look and feel amazing is brilliant. The ease of use is awesome (a little clunky) but when you need to make adjustments the window seams to close and you have to start over when switching between DAW and TopBox. I have found the missing piece and am thrilled to have it.

Please update cabs. Also plugs would be huge. It comes with a great limited plug but that’s really all it comes with - aside from a reverb and delay. It’s awesome still but could use some updates.

Sam L

r. seo

June 14, 2019

upgrade please

this is very usefull, I'm playing back on my VOX HWX1 and it is so pleasant.
BUT, it desyncrhonises in logic pro x while recording resulting in a crazy depitch digital noise... like a drunk DJ.
Otherwise, this is going to be really good when upgraded.

M. Music

June 10, 2019

Mediocre reactive load and no updates so far?

I've got the OX for over 14 months now and found out the impedance curve of the OX reactive load is based on a 'bathtub', not a real speaker cab as they claim, its similar to the Two Notes Captor load. It lacks the low resonance peak, so their is no low frequency amp response. For a 1300 euro load box you would expect more! As an alternative i use the OX now with the Suhr Reactive Load and OX load in parallel which makes my amp respond much better and makes the cab modeling sound better, especially with the 4x12 and 4x10 cabs.

No updates, no platform, no way to backup your presets. I gave them 3 starts when i bought it but now i give them 2 stars as its way overpriced for what you get in this box. The cab modeling software sounds great but a simple native plugin would do it for me as the load is mediocre and the IO limited.

m. pilsworth

May 20, 2019

Just what I have been looking for...would like ditch the ipad though

I use mine mostly for home recording and love it - the build quality inspires confidence and being able to overdrive at midnight without causing a riot with the neighbours is a dream come true. To me the sound quality is amazing and find the presets a great starting point for experimentation. Don't have too much of an issue with the lack of XLR as my Apollo Twin only has trs line inputs anyway. I have just started using a Windows based system and would very much like to ditch my ipad and hook up to my PC with USB though.